Ag包覆MnO锂离子电池负极材料的合成及性能

Preparation and properties of Ag-coated MnO as cathode material for lithium-ionic batteries

通过热分解MnCO3和AgNO3的方法制备了具有Ag包覆结构的MnO微米球。分别采用XRD、SEM和恒流充放电技术考察了其晶体结构、颗粒形貌和电化学性能。分析结果表明,该MnO/Ag复合材料结晶度良好,呈球状,直径约1.2μm,Ag包覆在MnO球体表面。当充放电电流密度为34.8mA/g时,MnO/Ag复合材料的首次库伦效率高达70.0%,初始可逆比容量为805.3mA.h/g,经30周循环后,其放电比容量仍保持在407.8mA.h/g。当电流密度增加到190.5mA/g时,其放电比容量仍有320mA.h/g。

Ag coated MnO microsphere was prepared by decomposition MnCOa and AgNO3. The structure,mor phology and electrochemical properties of the products were investigated by XRD, SEM and constant current discharge charge test. The results of XRD and SEM showed that MnO/Ag composite was sphere-like with good crystallinity,and it＇ s diameter was about 1.2μm. Ag was coated on the surface of MnO microsphere. It could deliver a reversible charge capacity of 805.3mAh/g with an initial columbic efficiency as high as 70.0% at the current density of 34.8mA/g,and the rest spe cific discharge capacity was 407.8mAh/g after 30 cycles. It released a capacity of 320mAh/g when tested at a higher current density of 190. 5mA/g.